Optical switch with low pressure bubble

Abstract

An optical switch is presented. In a first state, a trench is filled with index matching fluid so that light from a first waveguide passes through the trench to a second waveguide. In a second state, a bubble is formed within the index matching fluid so that light from the first waveguide is reflected at the trench to a third waveguide. The bubble is formed by heat so that volume of the bubble is substantially less than total volume of the trench, resulting in pressure within the bubble not being substantially increased by pressure exerted by sidewalls of the trench.

1. An optical switch, comprising:
 a first waveguide; 
 a second waveguide; 
 sidewalls that form a trench, including a first sidewall impinging the first waveguide and a second sidewall impinging the second waveguide, wherein the first waveguide and the second waveguide are positioned so that when the optical switch is in a non-reflection mode, light travels between the first waveguide and the second waveguide; and, 
 a heating system that forms a bubble within the trench, wherein when forming the bubble within the trench, the heating system conducts more heat to the first sidewall than to the second sidewall so that the first sidewall is hotter than the second sidewall. 
 
     
     
       2. An optical switch as in  claim 1  wherein when the optical switch is in the non-reflection mode, light travels from the first waveguide to the second waveguide. 
     
     
       3. An optical switch as in  claim 1  wherein the heating system includes:
 a heater; and, 
 a pillar that extends from the heater to the first sidewall. 
 
     
     
       4. An optical switch, comprising:
 sidewall means for forming a trench, the sidewall means including a first sidewall and a second sidewall; 
 first waveguide means for directing light, first waveguide means impinging the first sidewall; 
 second waveguide means for directing light, the second waveguide means impinging the second sidewall, wherein the first waveguide means and the second waveguide means are positioned so that when the optical switch is in a non-reflection mode, light travels between the first waveguide means and the second waveguide means; and, 
 heating means for heating the trench so that a bubble is formed in the trench, the heating means being arranged to disproportionately heat the first sidewall so that when forming the bubble within the trench, heat from the heating system is disproportionately conducted to the first sidewall so that the first sidewall is hotter than the second sidewall. 
 
     
     
       5. An optical switch as in  claim 4  wherein when the optical switch is in the non-reflection mode, light travels from the first waveguide means to the second waveguide means. 
     
     
       6. An optical switch as in  claim 4  wherein the heating means includes:
 a heater; and, 
 a pillar that extends from the heater to the first sidewall. 
 
     
     
       7. A method for operating an optical switch, comprising:
 filling a trench with index matching fluid so that light between a first waveguide and a second waveguide passes through a trench; and, 
 forming a bubble within the index matching fluid so that light from the first waveguide is reflected at the trench to a third waveguide; wherein the bubble is formed by heat so that a first sidewall of the trench is heated to be hotter than a second sidewall of the trench, wherein the first sidewall impinges the first waveguide and the second sidewall impinges the second waveguide. 
 
     
     
       8. A method switch as in  claim 7  wherein when the trench is filled with index matching fluid, light travels from the first waveguide through the trench to the second waveguide. 
     
     
       9. A method as in  claim 7  wherein forming the bubble includes
 using a heater to produce the heat; and, 
 using a pillar to spread the heat over the first sedewall.